In traditional methods for performing coronary artery bypass surgery, a segment of a blood vessel is harvested from another portion of the body and is used as an autogenous graft. The graft is typically sutured onto the coronary artery so as to bypass the stenosed area and restore adequate blood flow distal to or downstream from the blockage. Often in such a procedures, the saphenous vein is harvested from the surgical patient's leg and subsequently used as the graft vessel. In a large number of cases, the wound created in the leg is slow to heal and the patient endures considerable pain and irritation. In addition, surgeons have learned that, in general, an artery rather than a vein serves as a better, long term bypass graft.
Many surgeons prefer to use one of the internal mammary arteries (IMA) as the bypass graft. The descending IMA's are located within the thoracic cavity of the patient along each side of the sternum of the rib cage. The IMA is in close proximity to the heart and therefore it is not necessary to completely remove it from the patient. To prepare the IMA, the side branches of the IMA are first hemostatically severed and the main trunk of the vessel is occluded with a clamp. The IMA is then severed at a point just above to the patient's diaphragm so that it is mobilized. However, the IMA is never disconnected from its original blood supply. The freed end of the IMA is then anastomosed to a coronary artery, such as the left anterior descending (LAD) coronary artery, just distal to the stenosis. This procedure requires significant access and visibility into the upper thoracic cavity for the surgeon. The surgeon must free the IMA from the "ceiling" or wall of the internal thoracic cavity, while at the same time being very careful not to puncture or otherwise traumatize the IMA. The side branches of the IMA must be located and transected, usually by using an electrosurgical device, with minimal blood loss.
The most commonly used method of access to the thoracic cavity for the mobilization of the IMA and the anastomosis of it to the LAD coronary artery is a medial sternotomy. For this procedure, a longitudinal incision is made through the patient's sternum on the midline of the chest. Then a surgical retractor is used to spread and hold apart the left and right rib cages, creating an opening which is about four inches wide. The muscles and other tissues of the chest wall are significantly traumatized by this procedure, and the post-operative healing process for the rejoining of the split sternum is sometimes very slow. As a result, the patient endures significant pain and the recovery time is long. In some cases there are significant complications and occasionally follow-up surgical procedures are required.
In recent years, new methods of access into the thoracic cavity have been developed. One minimally invasive method is called a mini-thoracotomy and involves access through an incision running intercostally (between two ribs) of the left chest wall. A surgical retractor, such as the one used for a traditional sternotomy, is used, but in this case the superior and inferior rib cages of the left chest are only spread apart about two inches, thus resulting in much less overall trauma to the bones, muscles, and other tissues in the chest. Subsequently, the patient endures less pain and irritation following the surgery, and the recovery time is significantly decreased.
The mini-thoracotomy method of access to the thoracic cavity, however, has propagated the need for new surgical tools and methods because the opening into the thoracic cavity is considerably smaller than for the sternotomy. Also, since the IMA is attached to the thoracic cavity wall, the angle of approach the surgeon must use through the opening is very difficult since the inferior rib cage tends to obstruct the manipulation of surgical devices used for the procedure. Many of the new surgical retractors used in thoracic surgery have a rib elevator, which tilts the retractor at an angle so as to give the surgeon better access to the thoracic cavity. However, because of this change in the retractor to thoracic surgery, hospitals must now stock both the new retractors and the traditional retractors used in medial sternotomies.
There has, therefore, been a need for a device that can elevate surgical retractors at angles, but which are separate from and readily attachable to such retractors. In addition, there has been a need for such a device which is adaptable for use with many of the commercially available surgical retractors. Furthermore, there is a need for such a device which is easy and quick to set-up, given the importance of minimizing the length of time of the surgical procedure. Also, considering the high cost of surgical procedures today, it is important that such a device be easy to clean and sterilize for reuse, or that it be low cost and disposable.
Finally, there is a surgical need for a device which can be attached to any of numerous surgical retractors in use today, which can provide another means for support or attachment of other surgical devices used in the procedure. Often the surgeon wishes to hold or stabilize an organ or tissues within the cavity, and attach or support an ancillary holding tool on a fixed structure so that an assistant does not have to maintain the position of the holding tool throughout the procedure. Yet the surgical retractor arms are too far away from the organ or tissue of interest to be used as a platform. What is needed is a bar or bridge that can attach to the arms of the surgical retractor and cross over the opening nearer to the organ or tissue of interest. Then this bridge can be used as a platform for supporting or attaching the ancillary holding device.